LesDingeriesDeDjalimSurOpenGL/assets/shaders/lighting_spot.frag
2025-10-24 09:50:55 +02:00

88 lines
2.7 KiB
GLSL

//-----------------------------------------------------------------------------
// Fragment shader for spot light
//-----------------------------------------------------------------------------
#version 330 core
struct Material
{
vec3 ambient;
sampler2D diffuseMap;
vec3 specular;
float shininess;
};
struct SpotLight
{
vec3 position;
vec3 direction;
float cosInnerCone;
float cosOuterCone;
vec3 ambient;
vec3 diffuse;
vec3 specular;
int on;
float constant;
float linear;
float exponent;
};
in vec2 TexCoord;
in vec3 FragPos;
in vec3 Normal;
uniform SpotLight spotLight;
uniform Material material;
uniform vec3 viewPos;
out vec4 frag_color;
vec3 calcSpotLight();
void main()
{
// Ambient -------------------------------------------------------------------------
vec3 ambient = spotLight.ambient * material.ambient * vec3(texture(material.diffuseMap, TexCoord));
vec3 spotColor = vec3(0.0f);
// If the light isn't on then just return 0 for diffuse and specular colors
if (spotLight.on == 1)
spotColor = calcSpotLight();
frag_color = vec4(ambient + spotColor, 1.0f);
};
//--------------------------------------------------------------
// Calculate the spotlight effect and return the resulting
// diffuse and specular color summation
//--------------------------------------------------------------
vec3 calcSpotLight()
{
vec3 lightDir = normalize(spotLight.position - FragPos);
vec3 spotDir = normalize(spotLight.direction);
float cosDir = dot(-lightDir, spotDir); // angle between the lights direction vector and spotlights direction vector
float spotIntensity = smoothstep(spotLight.cosOuterCone, spotLight.cosInnerCone, cosDir);
// Diffuse -------------------------------------------------------------------------
vec3 normal = normalize(Normal);
float NdotL = max(dot(normal, lightDir), 0.0);
vec3 diffuse = spotLight.diffuse * NdotL * vec3(texture(material.diffuseMap, TexCoord));
// Specular - Blinn-Phong ----------------------------------------------------------
vec3 viewDir = normalize(viewPos - FragPos);
vec3 halfDir = normalize(lightDir + viewDir);
float NDotH = max(dot(normal, halfDir), 0.0f);
vec3 specular = spotLight.specular * material.specular * pow(NDotH, material.shininess);
// Attenuation using Kc, Kl, Kq -----------------------------------------------------
float d = length(spotLight.position - FragPos); // distance to light
float attenuation = 1.0f / (spotLight.constant + spotLight.linear * d + spotLight.exponent * (d * d));
diffuse *= attenuation * spotIntensity;
specular *= attenuation * spotIntensity;
return (diffuse + specular);
}